The purpose of the present project is to provide identification criteria (with supporting data) for certain streptococci considered to be potentially cariogenic. In addition, the immunofluorescent capabilities of several laboratories have been joined in collaborative research designed to develop FA reagent grade conjugates specific for certain plaque streptococci. Numerical taxonomic methods, other computer techniques, as well as conventional methods are being used to analyze the data from over 700 strains to develop differentiating criteria. Colored plates are being prepared to portray representative colonial types. Efforts in fluorescent antibody research have resulted in the development of improved immunization schedules, higher titered antisera, the optimal F/P ratio for conjugates and major advances in immunoabsorption methods to improve the specificity of S. mutans conjugates. A new column serum fractionation method and EDTA-Cellulose- Bacterial Column absorption have been developed. Improved methods for labeling conjugates with rhodamine have been developed.